Twenty-nine of the 30 soldiers reported lost to 5th Brigade, 2nd Infantry Division since it deployed in July were killed in bomb attacks. The most recent casualty reported by the Stryker brigade, Staff Sgt. David H. Gutierrez, was memorialized Monday at Fort Lewis. He was killed by a bomb blast on Christmas Day while on foot patrol.

The brigade has encountered almost 600 bombs — known in military circles as an improvised explosive device, or IED. The detonation rate has been about 50 percent.

Twenty-one Stryker vehicles have been damaged beyond repair.

"It's an increasing and significant threat, but there's also an increasing and significant effort to defeat it," said Col. Jeffrey Jarkowsky, who last year commanded Joint Task Force-Paladin, the American military's main counter-IED unit in Afghanistan.

"That being said, we've got to do more," Jarkowsky said. "We've clearly got to do more."